Spiral singulator

ABSTRACT

Log indexing apparatus includes a frame and a series of laterally spaced spiral rolls that are inclined from front to back between the infeed and the outfeed, and are also inclined sideways. The spiral rolls are rotated synchronously and are arranged so that the gaps between the flights of the spirals define an upward moving log-receiving trough across the width of the device. The sideways inclination reduces the tendency of the logs to ride on the edges of the flights of the spirals.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Continuation-in-Part of U.S. application Ser. No. 09/775,328filed Feb. 1, 2001, entitled SPIRAL SINGULATOR, U.S. Pat. No. 6,419,080.

TECHNICAL FIELD OF THE INVENTION

This invention relates to devices for unscrambling, singulating andending logs.

BACKGROUND OF THE INVENTION

The invention is used to unscramble bundles of logs and to promote thelogs from the bundle to another, usually higher, location. Generallyspeaking, devices that do this are well known. Such devices aresometimes called indexing apparatus, unscramblers or singulators. Theterm “singulator” refers to the fact that the devices are usuallydesigned to deliver a single log at a time to an outlet of the device.

Examples of prior art unscrambling and singulating devices are found inU.S. Pat. No. 5,653,570 to Weirathmueller; U.S. Pat. No. 5,257,688 toFridlund; U.S. Pat. No. 5,423,417 to Redekop and Canadian Patent No.1,091,611 to Halistrom.

One form of singulator that is relatively well known comprises a seriesof steps moving along an incline from an inlet location to an outletlocation. Two groups of reciprocating cooperate so as to graduallypromote logs toward the outlet. Such devices are typified by CanadianPatent No. 1,277,682 to Ekholm.

Another form of singulator is described in U.S. Pat. No. 5,119,930 toStelter. The '930 patent relies on multiple stages of movable quadrantsto promote and singulate logs. The top portion of each quadrant presentsa log supporting shelf that diminishes in size against a fixed surfaceas the quadrant moves through an arc so as to limit the number of logspromoted to the next stage.

The foregoing systems each involve step-wise reciprocating motion. Suchmotion in heavy machinery generates significant noise, and therepetitive contact between parts causes considerable wear.

It is an object of the present invention to provide an alternative yeteffective approach to unscrambling and singulating logs.

It is a further object of this invention to provide such a device thatis self-cleaning, that automatically ends logs, and in which both noiseand wear is reduced in relation to prior art systems.

SUMMARY OF THE INVENTION

The present invention provides a series of laterally spaced inclinedspiral rolls extending between an inlet location where logs are receivedin a bundle, and an outlet location at a higher elevation than the inletlocation.

The outlet is rearwardly offset in relation to the inlet so that thespiral rolls have a front to back inclination. The spiral rolls of theinvention are also inclined sideways, i.e. they define on angle inrelation to the feed direction. The spiral rolls comprise a pipe rolland a flange or “flight” wrapped around the pipe roll to define a spiralor helix about the length of the pipe roll. The gaps on the pipe rollbetween successive revolutions of the flight are aligned with the gapson the adjacent spiral rolls. The series of adjacent gaps across theplurality of spiral rolls defines an elongated log-receiving trough. Thespin of the spiral rolls is also synchronized so as to promote thelog-receiving trough in an even upward motion. In the area of theinfeed, the action of the spiral flights digging into the log bundleassists in dislodging individual logs and urging them into thelog-receiving trough.

The resulting device has the advantage of continuous action, therebyavoiding the repetitive loud banging associated with prior artsingulators, and reducing wear on the moving parts.

Another advantage of the invention is that the logs are continuously“ended” in one direction by the turning action of the spiral rolls.Ending the logs refers to aligning the end of a log against a referencesurface. Such ending assists in measuring the logs and in controllingsubsequent advancement and cutting operations for the log.

It is a further feature of the invention that the sideways inclinationof the spiral rolls allows the logs to more closely abut the face of thehelical flights. Without such a sideways angle, the logs would ride onthe sharp edges of the flights thus impeding smooth progress of the

Other aspects of the invention will be appreciated by reference to thedetailed description that follows and are more particularly defined bythe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more fully appreciated by reference to thefollowing description of the preferred embodiment and by reference tothe drawings thereof in which:

FIG. 1 is a view of the preferred embodiment of the invention; takenfrom a point above and normal to the spiral rolls;

FIG. 2 is a side elevation of the preferred embodiment;

FIG. 3 is a front view of roller chain and bracket assemblies for two ofthe spiral rolls;

FIG. 4 is a view of an alternative embodiment of the invention, takenfrom a point above and normal to the spiral rolls; and

FIG. 5 is a side elevation of the alternative embodiment of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a spiral singulator 10 according to the invention. Aplurality of spiral rolls 12 are mounted on a frame 14.

Referring FIG. 2, the spiral singulator 10 delivers logs from an inletlocation (infeed) 16 where the logs are received in a scrambled andunsingulated bundle, to the outlet location (ouffeed) 18 to which thedevice delivers singulated and ended logs. Infeed 16 includes aninclined skid plate 20 for receiving and holding a bundle of randomolydistributed logs. The outfeed location is rearwardly offset in relationto the infeed location.

Frame 14 comprises vertical members 22 at the rear of the singulator,horizontal base members 24 extending from front to back of thesingulator and diagonal bracing members 26. Upper cross member 28,intermediate cross member 30, and cross members 32 and 34 extend acrossthe width of the device.

Skid plate 20 extends at an incline from intermediate cross member 30upward and toward the front of the singulator. The bottom of skid plate20 is braced against a series of spaced bearing pedestals 36, only oneof which is visible in FIG. 2. The bottom of the spiral roll extendsthrough an opening at the bottom of skid plate 20, as best illustratedin FIG. 3. The top of the skid plate is braced against an infeed frame38 (FIG. 2).

Referring to FIGS. 1 and 2, a plurality of spiral rolls 12 are spacedlaterally from one another across the width of the singulator 10. Spiralrolls 12 are inclined from front to back between the bottom portion ofthe infeed 16 and the ouffeed 18. This front to back inclinationcorresponds to the feed direction indicated by arrow 47. It will beappreciated that the feed direction extends along a straight linebetween the infeed and the ouffeed locations, the line being normal toboth. In the preferred embodiment, the front to back inclination of thespiral rolls (as best seen in FIG. 2) is about 50° to the horizontal.However the specific angle of front to back inclination will depend onthe size of the logs to be fed by the device, the height of the flightson the pipe rolls and the number of spiral rolls available to support agiven log. It is contemplated that any angle between 10° and 80° wouldbe within the scope of the present invention.

Each spiral pipe roll 12 comprises an elongated pipe roll 40 to which aflange or flight 42 has been helically welded about the length of theroll to define a spiral shape. The spiral configuration defines a seriesof gaps 44 between successive revolutions (e.g. 46, 48) of the flight.The flights may be arranged in either a right hand or left hand screwconfiguration, the right hand configuration being shown in the drawings.Thus rotation of the spiral rolls clockwise (as indicated by arrow 17)when viewed from the top of the spiral rolls promotes the gaps upward.

The laterally adjacent plurality of spiral rolls 12 are arranged suchthat their gaps 44 and flights 42 are horizontally aligned as seen inFIG. 1 so as to define an elongated log-receiving trough 49 extendingacross the width of the singulator 10.

The flights 42 on the spiral rolls 12 define a helical face angle,namely the angle defined between the face of the flight and thelongitudinal axis of the roll.

In addition to being inclined from front to back, spiral rolls 12 arealso inclined sideways as seen in FIG. 1, i.e. their longitudinal axesdefine an angle of less than 90° in relation to the transverse axis(side to side) of the singulator. In the preferred embodiment, thisangle is about 71°. Taken in relation to the vertical, the sidewaysangle is about 19°. This may also be viewed as an offset angle inrelation to the feed direction 47. This inclination allows the logs inthe log-receiving trough 49 to come into fuller face contact with theface of the flights 42. Absent such inclination, the logs would rest onthe relatively sharp outer edges of the flights thereby causing theflights to dig into the logs, or to catch on branches, notches orimperfections in the logs and thereby impede progress of the logs.Maximizing contact with the face of the flights and minimizing contactwith their edges encourages smooth promotion of the logs upwards. Thespecific angle of sideways inclination may vary, however preferably thesideways angle as defined in relation to the vertical to be close to thehelical face angle so as to allow presentation of the face of the flightto the side of the log. It is contemplated that any sideways angle inrelation to the vertical that is within 35° of the helical face angle iswithin the scope of the invention.

Each spiral roll 12 is mounted for rotation at its lower end in abushing 50 within a bracket 52. Each bracket 52 is mounted on a supportplate 53 mounted on a block 52 that is in turn secured to a bracket 53and a bearing pedestal 36. Bearing pedestal 36 extends between crossmember 32 and intermediate cross member 30. The bearing pedestals mayalso be used to support the skid plate 20.

The top of the spiral roll is mounted for rotation on an end plate 55extending diagonally from upper cross member 28.

Referring to FIG. 3, the lower end of each spiral roll include sprockets54, 56 at each side of bushing 50. A roller chain 58 engages the uppersprocket 56 of one spiral roll 12 a and the lower sprocket 56 of theadjacent spiral roll 12 b. This drive linking across successive spiralrolls allows them to be driven in synchronism by a motor (not shown). Asa result, coordinated rotation of the spiral rolls will promote thelog-receiving trough 49 upwards at a rate consistent across the width ofthe singulator.

The lateral spacing between adjacent spiral rolls is approximately onefoot in the preferred embodiment. This allows logs and larger debris tobe promoted upward while allowing smaller debris to fall between therolls. This provides a self-cleaning feature for the device and may beeffective for spacings between 6″ and 18″.

Dragon backs 60 of a thickness of about ½ of an inch are providedbetween adjacent spiral rolls 12. The teeth of the dragon backs serve toengage the upward moving log and cause it to rotate. This rotation inturn expels other logs that might have seated themselves in the samelog-receiving trough. This feature enhances the singulating activity ofthe device to ensure that only one log at a time is promoted to theouffeed. Dragon backs 60 are mounted on bars 61 extending parallel tothe spiral rolls 12 from the bottom of the rolls to about the mid pointof the rolls. Bars 61 are supported by frame members (not shown) suchthat logs in log-receiving trough 49 do not come into contact with theroll surfaces in the area of the gaps 44 until the log has been promotedin the feed direction past the dragon backs 60.

As all spiral rolls 12 rotate in synchronism, logs are picked out of thebundle of logs at the infeed 16 by the action of flights 42 and one ormore logs are urged into the log-receiving trough 49. The trough 49moves upward in the direction of arrow 47. As the trough moves past thedragon backs 60 additional singulating takes place. The log isultimately discharged at the ouffeed 18 onto ramp 63 and a conveyor.

An alternate method of causing the log to rotate instead of using dragonbacks 60 is to incline the spiral rolls 12 several degrees less than thefull face angle of the flights 42. As a result the edges of the flightscome into contact with the logs rather than the full face of the flight.The rotational action of the edges of the flights coming into contactwith the log at this reduced angle will tend to lift the log slightly,thus causing it to rotate. This is the same effect the dragon backshave, but as a result of contact with the edges of the flights insteadof the dragon backs. This rotation expels other logs that might haveseated themselves in the same log receiving trough. Bars 61 are stillused with this roll configuration.

In an alternative embodiment illustrated in FIGS. 4 and 5, the bars, ordecline retarder fins 61 a, are positioned such that they decline inrelation to the spiral rolls 12. Because of the decline slope of thedecline retarder fins 61 a, logs come into increased contact with thespiral flight 42 as they are promoted in the feed direction. Therefore,at the infeed point 16, where the bars 61 a extend the furthest distanceabove the surface of the rolls 12, the logs have minimal contact withthe spiral flight 42, thereby enhancing the singulation activity as logsare only drawn off the bottom of the deep pile of logs. This angledpositioning of the decline retarder fins 61 allows for preliminarysingulation at the infeed 16 such that one or more logs are urged intothe log-receiving trough 49. Further singulation takes place throughrotation imparted by edges of the flights as described above.

As a further alternative, not shown, dragon backs 60 could also beaffixed to the decline retarder fins 61 a in order to impart additionalrotation to the logs. Different combinations of the slope of the bars 61and 61 a, the incline of the spiral rolls and the use of dragon backsmay be used in order to control the singulation process of differentsized logs.

The turning action of the spiral rolls is partially imparted to the logby the face of the flights 42 resulting in a slight displacement of thelog in the direction of arrow 67. More pronounced lateral displacementoccurs when the log rests on the body of the spiral roll in the area ofgaps 44. The turning action of the roll propels the log toward an endingside plate 66. As a result, the logs are effectively ended againstending side plate 66 by the time they reach the ouffeed. As prematureending may result in dragging of the log along side plate 66, the bars61 and dragon backs 60 are arranged to be at a higher elevation than thebody of the spiral rolls in the area of the gaps 44 adjacent the bars.By doing so, aggressive ending action is delayed until the logapproaches the ouffeed 18.

It will be appreciated by those skilled in the art that certaindeviations from the preferred embodiment described herein may bepractised and certain alterations may be made without departing from thescope of the invention.

What is claimed is:
 1. Log indexing apparatus comprising a plurality oflaterally spaced, parallel spiral rolls extending between an inletlocation where logs are received in a bundle, and an outlet location ata higher elevation than the inlet location, and wherein: each of saidspiral rolls has flights extending spirally along the length of therolls; said outlet location is rearwardly offset from said inletlocation; said spiral rolls have a front to rear inclination; a feeddirection is defined as being along a line normal to said inlet locationand to said outlet location and extending between them and said spiralrolls are further inclined laterally so as to define an angle inrelation to the feed direction; each spiral roll includes gaps betweensuccessive revolutions of the flight on said spiral roll, and whereinthe gaps on adjacent spiral rolls are horizontally aligned to defineelongated log-receiving trough; and decline retrarder fins extendgenerally in said feed direction and are located between adjacent spiralrolls.
 2. Log indexing apparatus as in claim 1 wherein means areprovided to prevent logs from coming into contact with the shaft portionof the spiral rolls in the lower half of the apparatus.
 3. Log indexingapparatus as in claim 2 wherein said means comprises providing saiddecline retarder fins at a higher elevation than the shaft of the spiralrolls in the area of said gaps.
 4. Log indexing apparatus as in claim 3wherein said decline retarder fin is at its highest elevation above saidshaft portion at said inlet location, said elevation above said shaftportion decreasing in said feed direction.